Goofs

When Annie says good-bye to her butler, she says she'll see him in eight weeks. When Annie is driving back home with her father she says camp was eight weeks' long. However, when Hallie is talking to her mother at the dinner table, Elizabeth says camp was six weeks long.

When the camera zooms in for Annie's skinnydipping, you can see her ears are pierced. Later in the plot, we find out that Annie's ears are not pierced.

After Elizabeth exits the car in front of the hotel, Martin closes its door. But it's open again when we see a close-up on Hallie.

When Hallie and Annie drag Meredith's air mattress into the lake, they are shown wading several inches into the water in order to push it into the current. However, when they are watching Meredith drift away, their shoes/bottoms of their pants are completely dry.

The scene where Annie is sitting down about to get her hair cut, she obviously has holes in her earlobes, when in fact Hallie pierces Annie's ears after her haircut.

When the kids arrive at camp the screen says 11 years and nine months later which would mean they had just turned 11. But they say they turn 12 in October which would make them more than 11 1/2.

When Hallie tells Annie about the idea to switch places, as the girls go back to bed, if you look very closely on the left side you can see Lindsay Lohan's acting double, Erin Mackey momentarily, right after Annie says "After all these years."

The opening sequence set aboard the ocean liner QE2 was obviously filmed aboard the museum/hotel ship RMS Queen Mary in Long Beach, CA. The equipment on the bridge shown in the movie (brass steering wheel, etc) is part of the Queen Mary tour and is far to antiquated to be in service on the QE2 in 1986. The dark wood interiors are a giveaway as well. Finally, when Nick and Elizabeth are looking up at the fireworks, you can see the coin operated binoculars from the Queen Mary in the background along the rail. The QE2 did not have those on her deck.

At the end of the movie, Hallie says that the Concorde gets you here in half the time. There were no Concorde flights from California to London because the Concorde had a range of 4500 miles, yet London is 5400 miles away. The plane would have crashed into the ocean 900 miles shy of London. In addition, the "half the time" rule of thumb doesn't apply to routes where a significant portion is overland. Because of the sonic boom, the Concord was not allowed to use its full speed when over land.

They could have flown a conventional aircraft to the east coast then boarded a Concorde but a nonstop flight on a conventional aircraft would get to London faster then stopping on the east coast for the Concorde.

When Hallie as Annie rings the real Annie from the phone booth a bell dings as she puts the handset back, this doesn't happen in British phone booths.

When Elizabeth is packing for her trip to meet Nick and switch back the two girls, Hallie comes into Elizabeth's room and tells her that she just talked to Nick and that he's excited to see her. After Elizabeth starts to freak out about the fact that Nick is "excited" to see her, she tells Hallie to go ask/see her "grandmafather." You can clearly tell that she says that and you can tell she realizes she said it because she turns around really quickly. However, the DVD commentary reveals that while this WAS a genuine mistake on Natasha Richardson's part, it's being in the film is not- director Nancy Meyers felt that it fit with Elizabeth's frazzled state at the time and opted to keep it in.

In the beginning of the switch, it begins with Hallie pretending to be Annie. At the end of the scene she says, "Speaking of dad, I wonder what he is doing right now?" But, a flight from the east coast to London is about seven and one-half hours, plus the time change in London, assuming it was noon in London it would be, four in the morning in California. In other words, Nick Parker would have picked Annie (pretending to be Hallie) up from the airport the day before.

However, Annie did not leave until some hours after Annie, and may not have been a non-stop flight. It was also much later than midday in London, as the time on Big Ben was 11:30 during the journey from the airport, several hours had passed since then.

When Hallie as Annie walks into the house in London for the first time, she clearly turns a knob on the door to walk in. When the shot changes as she walks through the door, the handle is gone.

A close-up shows Hallie's hand on the knob, as she pushes the door open. The scene cuts to a close-up of the exterior of the opening door with Hallie, seen from the back, entering. As a result of the change of both camera angle and zoom, Hallie's hand and the knob are out of frame. Inside, Hallie looks around. The scene is cut to show Hallie from the front, as the door behind her finishes swinging shut.

In the opening credits, when Elizabeth and Nick are signing the wedding certificate, though two different names are signed, the hand writing is the same.

When Nick and the girls return from the camping trip, they have a brief conversation with Liz and Nick before heading inside. During this conversation, when Nick is viewed on the left hand side of the screen, he is reflected in the glass of the door they are standing in front of. Although one of the twins is standing right next to Nick, we do not see her reflection, only Nick's. Even when she passes in front of the door, her reflection doesn't appear. (This is most likely a result of the camera tricks used to make Lindsay Lohan appear as twins.)

When the girls are in Meredith's tent during the camping trip, their figures are only silhouettes. One of the girls says something, and the other replies but the sound comes from the same source, proving that in that scene the crew used a lookalike (probably a stunt double) and had Lindsay Lohan say both lines.

At night, when the girls leave their tent to drag Meredith to the lake, the leaves of the trees behind the tent are clearly visible through the open tent door indicating that the tent is open on the other side as if there was nothing there.

In the scene where Annie is looking at Hallie's house, Hallie points to her father in the picture. Hallie's arm noticeably gets shorter, in order to point at the picture. If her arm was unedited, it would point at Annie's wrist.

When Hallie wins at poker the first time the twins play, she produces a royal flush and and says "in your honor" to Annie, obviously referring to her British nationality. However, the music being played in the background is the first notes to La Marselleise, which is not only the French national anthem, but also revolutionary and anti-monarchic.

Early in the film, Annie and Hallie begin to discover their similarities, one of which is that they both like Oreo cookies with peanut butter. However, Oreos were not widely available in the UK in 1998; they started to become available in packs of four about five years after this film was made. Growing up in England, Annie would probably never have tasted an Oreo.

When Hallie notices that Annie doesn't have pierced ears, it is almost clear that Hallie is mouthing "What?" while Annie is the one saying it.

After the family returns from the camping trip, Elizabeth and Nick are talking on the porch. When Elizabeth says, "Well, they went out for a picnic," Her back is turned but her mouth is not moving.

At Camp Walden, when the water ballons are falling onto Annie's head, you can see the arm of a crew member pushing the largest balloon to fall over.

As the twins drag Meredith out of the tent down to the lake a frame with wheels can clearly be seen under the inflatable bed.

The bird that lands on Meredith, waking her when she is on the air mattress in the middle of the lake, is a Red-Crested Turaco, indigenous to central Africa, not northern California where the scene supposedly takes place.

Liz says after the fight that broke the couple up, she packed up and took her first 747 (and that Nick didn't come after her). She doesn't say anything about taking Annie nor does she state when she and Nick made arrangements to have separate custody of the girls.

In the hotel scene where the parents can not tell the girls apart and therefore agree to the camping trip, the dog would have been able to tell the girls apart.

Meredith tells Annie (as Hallie) that she is going to marry Nick in two weeks and nothing "Hallie" does can stop it. Later in the movie, they are supposedly at the Stafford and trying to decide if they want to have the wedding there. If the wedding was less than two weeks away, the invitations would have already been sent out with a location on them.

While hiking to the lake, Nick had a decent size backpack. The girls backpacks were normal and Meredith's was very small. Yet at the campsite, Meredith had a very large tent and the girls had a nice size one as well. They all had air mattress and sleeping bags. They also brought a coffee pot, skillet, plates, and silverware. Meredith had a change of clothes. There is no way they could have fit all of these things into 4 backpacks.

No two people, not even identical twins, have the exact same number and arrangement of freckles on their faces.

In the cabin when the balloons are falling on Annie, she looks up as the biggest one is about to fall. She moves to the side so she's right under the balloon.

In the very last shot of the film, right after Nick and Elizabeth have remarried on the ship, there is a close up photo of them with no wedding ring on Elizabeth's finger.

When Martin walks into the hotel room in his bathing suit, you can see half of acting double Erin Mackey's face as Hallie before she turns around to look at Martin.

In the scene when Annie and Hallie fence, they often turn around. This is a red card offense and means that the person who did not turn will get a point and the fencers stop and start again. If the teacher knew the rules for fencing, she would have stopped the match.

In the scene after Nick falls into the pool, there are several shots of Meredith in which both of her hands are visible but there is no engagement ring, despite the fact that she and Nick are at the hotel to plan their wedding, and she asked Elizabeth to make her wedding dress.